Conformable, nonwoven three-dimensional fibrous surface finishing articles are known to remove corrosion, surface defects, burrs, and the like as well as to impart desirable surface finishes on various articles of aluminum, brass, copper, steel, and wood, for example. Such articles include discs, endless belts and pads made according to the teachings of U.S. Pat. No. 2,958,593 issued to Hoover et al. Such nonwoven surface finishing articles have not been entirely satisfactory because they can get snagged on sharp edges or stretch and break when in the form of endless belts. It is desirable, therefore, to develop surface finishing articles comprising nonwoven portions which are strong and resistant to stretching and snagging during use.
Efforts to reinforce nonwoven surface finishing products have included needle tacking the three-dimensional web, affixing the web to a woven support backing or a combination thereof. The resulting articles, although widely used, have also been less than satisfactory in some applications. Needle tacking of the nonwoven web, for example, produces densified areas which take on abrasive/binder coatings at higher loadings than other areas within the web. These densifted areas form harder, more aggressive abrasive surfaces which may scratch the workpiece in subsequent surface finishing applications. Additionally, woven support backings often lack sufficient conformability to match the contours on many surfaces, resulting in "edge cuts" where the edge of the moving belt aggressively cuts into the contoured areas of the workpiece. Finishing operations such as the final finishing of fine furniture, musical instruments, or performance articles such as skis, for example, are exemplary of surface finishing operations requiring improved surface finishing articles. Accordingly, there is a need for a nonwoven surface finishing article which is resistant to snagging, stretching and/or breaking during use while being flexible and conformable for use on contoured surfaces. Preferably, the nonwoven web in such an article would not include densified abrasive areas.
Other efforts to provide suitable nonwoven surface finishing articles have used an open mesh cloth to reinforce the nonwoven web. Frequently, the web is needle tacked and the needled fibers of the web project through the cloth. Such stretch resistant nonwoven surface finishing belts show improvements in snag resistance and in some uses on contoured surfaces where the belt is supported against the workpiece by a contact wheel. However, in applications where a stationary platen is urged against the belt, excessive friction between the platen and the nonwoven needled fibers protruding through the woven cloth generates significant heat which can abrade the platen during the operation. Moreover, the roughness of the nonabrasive surface of such belts can prevent the application of a uniform pressure by the platen and thereby prevent the smooth running of the belt over the workpiece. Therefore, a need exists for a surface finishing article suitable for use on contoured surfaces and which can be operated by use of a stationary platen to provide a consistent finish on the workpiece and without excessive wear of the platen. It would be desirable to provide such an article with a backing which provides a smooth, low-friction surface and wherein the nonwoven web lacks densified abrasive areas.